--- a/mercurial/error.py	Mon Jan 12 11:39:38 2009 -0600
+++ b/mercurial/error.py	Mon Jan 12 11:48:05 2009 -0600
@@ -56,3 +56,6 @@
 class AmbiguousCommand(Exception):
     """Exception raised if command shortcut matches more than one command."""
 
+# derived from KeyboardInterrupt to simplify some breakout code
+class SignalInterrupt(KeyboardInterrupt):
+    """Exception raised on SIGTERM and SIGHUP."""